nullptr

Recently tried the following program and it compiles, runs fine and produces expected output instead of any runtime error. #include <iostream> class demo { public: static void fun() { std::cout<<"fun() is called\n"; } static int a; }; int demo::a=9; int main() { demo* d=nullptr; d->fun(); std::cout<<d->a; return 0; } If an uninitialized pointer is used to access class and/or struct members behaviour is undefined, but why it is allowed to access static members using null pointers also. Is there any harm in my program? TL;DR : Your example is well-defined. Merely dereferencing a null pointer is

This question already has an answer here: What exactly is nullptr? 12 answers I know that in C++ 0x or NULL was replaced by nullptr in pointer-based applications. I'm just curious of the exact reason why they made this replacement? In what scenario is using nullptr over NULL beneficial when dealing with pointers? nullptr is always a pointer type. 0 (aka. C's NULL bridged over into C++) could cause ambiguity in overloaded function resolution, among other things: f(int); f(foo *); Shafik Yaghmour You can find a good explanation of why it was replaced by reading A name for the null pointer:

This piece of code conceptually does the same thing for the three pointers (safe pointer initialization): int* p1 = nullptr; int* p2 = NULL; int* p3 = 0; And so, what are the advantages of assigning pointers nullptr over assigning them the values NULL or 0 ? In that code, there doesn't seem to be an advantage. But consider the following overloaded functions: void f(char const *ptr); void f(int v); f(NULL); //which function will be called? Which function will be called? Of course, the intention here is to call f(char const *) , but in reality f(int) will be called! That is a big problem 1 , isn